Trophic transfer of microplastics in aquatic ecosystems: Identifying critical research needs

Abstract

Abstract To evaluate the process of trophic transfer of microplastics, it is important to consider various abiotic and biotic factors involved in their ingestion, egestion, bioaccumulation, and biomagnification. Toward this end, a review of the literature on microplastics has been conducted to identify factors influencing their uptake and absorption; their residence times in organisms and bioaccumulation; the physical effects of their aggregation in gastrointestinal tracts; and their potential to act as vectors for the transfer of other contaminants. Limited field evidence from higher trophic level organisms in a variety of habitats suggests that trophic transfer of microplastics may be a common phenomenon and occurs concurrently with direct ingestion. Critical research needs include standardizing methods of field characterization of microplastics, quantifying uptake and depuration rates in organisms at different trophic levels, quantifying the influence that microplastics have on the uptake and/or depuration of environmental contaminants among different trophic levels, and investigating the potential for biomagnification of microplastic-associated chemicals. More integrated approaches involving computational modeling are required to fully assess trophic transfer of microplastics. Integr Environ Assess Manag 2017;13:505–509. © 2017 SETAC Key Points The trophic transfer of microplastics are dependent on a variety of abiotic and biotic factors including the feeding strategies of the organisms within the food web, their exposure to these particles in their habitat, the physical and chemical characteristics of the particles, and their residence times within organisms. Limited field evidence from higher trophic level organisms in a variety of habitats suggests that trophic transfer of microplastics may be occurring concurrently with direct ingestion. Integrated approaches involving computational modeling will be required to fully assess trophic transfer of microplastics.